I know what you mean. If I am only selling one or two and I can make put them in a 11 x 8.5 envelope flat, you can send them by letter mail which is somewhat helpful. I just sent two NB size diapers via letter and it was about $4.50. It can't be more than 1 cm in height I think. Still expensive, but the best I could do. But you really have to flatten them! I stuck them in a ziplock back and sealed it right shut